diff options
Diffstat (limited to 'lib/sqlalchemy/orm/attributes.py')
| -rw-r--r-- | lib/sqlalchemy/orm/attributes.py | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py index 5ba8be439..b08c46741 100644 --- a/lib/sqlalchemy/orm/attributes.py +++ b/lib/sqlalchemy/orm/attributes.py @@ -1273,19 +1273,27 @@ def backref_listeners(attribute, key, uselist): if not child_impl.collection and not child_impl.dynamic: check_remove_token = child_impl._remove_token check_replace_token = child_impl._replace_token + check_for_dupes_on_remove = uselist and not parent_impl.dynamic else: check_remove_token = child_impl._remove_token check_replace_token = child_impl._bulk_replace_token \ if child_impl.collection else None + check_for_dupes_on_remove = False if initiator is not check_remove_token and \ initiator is not check_replace_token: - child_impl.pop( - child_state, - child_dict, - state.obj(), - initiator, - passive=PASSIVE_NO_FETCH) + + if not check_for_dupes_on_remove or \ + not util.has_dupes( + # when this event is called, the item is usually + # present in the list, except for a pop() operation. + state.dict[parent_impl.key], child): + child_impl.pop( + child_state, + child_dict, + state.obj(), + initiator, + passive=PASSIVE_NO_FETCH) if uselist: event.listen(attribute, "append", |